Factors Influencing the Efficacy of the Potential Microbial Herbicide Alternaria alternata (Fr.) Keissler on Amaranthus retroflexus (L.)
Abstract:Alternaria alternata, applied to run-off at 107 conidia ml-1 and given a 6 h dew period, caused an 88.5% reduction in dry weight of 4 to 5 true-leaf plants of Amaranthus retroflexus. This level of control was achieved whether the inoculated plants were grown in the glasshouse or outside. Formulation of the pathogen in oilseed rape emulsion reduced its dew period requirement from 24 h or more to 8 h or less. For example, with 106 conidia ml-1, equivalent effects were found with 8 h dew with emulsion formulation compared to 48 h dew with the Tween formulation. Allowing spray deposits to dry on inoculated plants for ca 7 h, before exposing to dew increased the efficacy of the pathogen.
Document Type: Research Article
Publication date: 2000-02-01